Display cards are often used to show merchandise in a store environment. Display cards are typically made from sheet material such as paperboard where the card may generally have a lower thickness than corrugated packaging materials. A transparent portion such as a blister may be provided in order to improve product visibility; such packages are referred to in the art as a “blister package.” For package strength and theft deterrence, the sheet material may be reinforced, for example made tear-resistant or tear-proof.
In one type of tear resistant structure, the front and back layers of paperboard may comprise unbleached paperboard, with the first side having a clay coating for a printing surface, and the second side having tear resistant and heat sealable properties. For example, the second side may be treated first with an extruded tie layer, then a laminated tear resistant layer, then an extruded or otherwise applied heat sealable adhesive layer. Thus the first side may be a printable “white” side and the second side is a heat-sealable “brown” side. Examples of a heat sealable tear resistant material are disclosed in U.S. Pat. No. 7,208,209 which is hereby incorporated by reference in its entirety.
Often the blister may include a transparent bubble portion defining a volume in which the product is contained, and a peripheral flange portion that may be trapped between a front and rear layer of paperboard. In such a case, there is usually an aperture in the front layer of paperboard, to accommodate the bubble portion of the blister. Usually the front layer of paperboard may have graphics printed thereon, for example on the outer or “white” side of a tear resistant paperboard. Typically these graphics do not extend behind the bubble portion of the blister, since the associated front layer material has been removed in creating the aperture. Thus the “brown” or inner side of the paperboard back layer shows behind the blister. It is difficult to print high quality graphics on the heat seal coating.